Retrieving ring for removable drilling bits



y 1950 c. c. KOELN 2,506,795

RETRIEVING RING FOR REMOVABLE DRILLING BITS Filed May 11, 1945 2 Sheets-Sheet 1 INVENTOR. 6/221. .6. K051.

ATTORNEY.

y 1950 c. c. KOELN 2,506,795

RETRIEVING RING FOR REMOVABLE DRILLING BITS Filed May 11, 1945 ZSheets- Sheet 2 \M/ i M J Q 1 3 16 3 F76. 3 m T IZ/ 3 2 3 E 24 25.- \i 25 23 Fla.

INVENTOR. CAQL 6. H051.

ATTORNEY.

Patented May 9, 1950 RETRIEVING RING FOR REMOVABLE DRILLING BITS Carl C. Koeln, St. Louis County, Mo.

Application May 11, 1945, Serial No. 593,196

9 Claims.

This invention relates to drilling mechanism and more particularly to a device for retrieving a removable drilling bit from the end of a drilling stem while the stem remains in the hole being drilled.

One of the objects of the invention is to produce improved means for disconnecting a removable drilling bit from the lower end of a drilling stem while said stem remains in the hole being drilled and for raising the bit to the top of the hole after it is disconnected.

Another object is to produce improved means for disconnecting a removable bit from a drill stem without the necessity of any rearward rotation of the stem and particularly where the bit is attachable by relative rotary movement between it and the stem.

Still another object is to provide improved means for turning a removable drilling bit rearwardly on a drilling stem while the stem is stationary to thereby disconnect it so that it can .be removed up the drill stem while said stem remains in the hole.

A further object is to associate with means for disconnecting a removable drilling bit from a drill stem other means for automatically fastening the bit to the means employed to accomplish the disconnection aiter the bit has been disconnected thus enabling the bit to be removed from the bottom of the hole along with said means employed to accomplish the disconnection.

A still further object is to provide improved means which, when lowered over' a drill stem, will produce a hammer blow turning force on a removable drilling bit so as to disconnect it from the drilling stem and without producing any turning force on the stem which could loosen its threaded joints.

Other objects of the invention will become apparent from the following description taken in connection with the accompanying drawings in which:

Figure 1 is 'a view partly in section showing "a removable drilling bit attached to adrill stem and a retrieving ring being lowered over the drill stem for disconnecting the bit and removing it from the hole without removing the drill stem;

Figure 2 is an enlarged view showing the relation of the retrieving ring and bit at the time the ring acts on the bit to produce a turning force;

Figure 3 is a cross-sectional view taken on the line 3-3 of Figure 2;

Figure 4 is a view of one-half of the ring as seen when looking at the inside;

Figure 5 is a top view of the half shown in Figure 4; and

Figure 6 is a view showing the relation of the ring and bit for removal up the stem after the bit has been disconnected from the stem.

Referring to the drawings and first to Figure 1, there is disclosed a drill stem I which is provided at its lower end with a specially constructed terminal section 2 to which a removable drilling bit, generally indicated by numeral 3, is attached. The drilling bit comprises a bit body 4 provided with a bore 5 permitting it to be slid up and down the drill stem. In order to attach the bit body to the drill stem the terminal section 2 is formed to provide L-shaped grooves 6 (one only :being shown) and cooperating with each groove is a pin 1 carried by the body. Each pin can be received in the open end of a groove and when the stem is turned it will be moved into the horizontal leg thereof to thus cause the drill bit to be attached for drilling operation, it being understood that the drill stem during drilling will rotate in the direction indicated by the arrow. The body of the removable drilling bit carries fixed cutters 8 and swingable cutters 9, the swingable cutters being movable to positions below the bottom of the drill stem in order to cut the central part of the hole. The movement of these swingable cutters to their operative positions occurs at the time the drilling bit reaches the end of the section 2 and is in a position to be connected to the drill stem by means of the L- shaped grooves and pins. Details of the mounting of the swinging cutters and the manner in which they are swung is not disclosed as it is believed that description thereof is unnecessary since the particular details of the drilling bit forms no part of the invention, outside of the fact that the bit is attached to and detached from the terminal section of the drill stem by a limited relative rotary movement. For a particular example as to how the fixed and swingable cutters are mounted in the drill body, reference may be made tomy co-pending application, Serial No. 534,185, for Removable drilling bit, filed May 5, 1944, now Patent No. 2,472,710.

In accordance with my invention I provide a special type of retrieving ring for disconnecting the drilling bit 3 from the drilling stem and for pulling it out of the hole being drilled without the necessity of removing the drill stem. This retrieving ring, which is indicated by the numeral [0, is shown in detail in the various figures. The ring consists primarily of a cylindrical member which is shown as constructed from two like of the cylindrical member.

semi-cylindrical sections H and I2. Since these sections are of identical construction the same reference characters will be employed to describe the detail thereof. The cylindrical member of the ring is formed by connecting the two semicylindrical parts together by bolt [3. The cylindrical member so formed has an inner diameter somewhat greater than the diameter of the drill stem.

To the inner surface of each of the semi-cylindrical sections are secured splines or ribs l4 having curved outer surfaces IS, the radius of curvature of which is just slightly'g-reater than that of the drill stem to permit free sliding onth'e stem. The splines have axially extending rear keys is which fit in axially extending grooves I! in the sections. Bolts l8 rhold the splines in position, the said bolts being accessible from the exterior of each section with their heads countersunk as shown. These splines M are arranged to cooperate with axially extending splines 19 carried as by welding on the outer surface of'drill stem I above the terminal sectionZ of the drill stem. The splines l9 are arranged to fit in the spaces or grooves between the splines M on the 1 and the splines 19 have V-shaped upper ends 2|...

Thus it is seen that the splines will assume cooperating relationship regardless of the particular rotative position the cylindrical member may be in when it reaches the terminal section 2.

Each semi-cylindrical section at its lower end is formed with two hooks 22 which have on their back sides cam surfaces 23, which surfaces'are angularly related to the axis of the section. When the two sections II and I 2 are secured together there is formed by the hooks and the cam surv faces four V-shaped notches 24 at the lower end These notches open in a direction away from the lower end of the cylindrical member and a hookextends circumferentially into a portion of an open'end of a notch. The surface 25 of the notch opposite the cam surface, which is a surface of the hook, eX tends in a substantial axial direction, as is clear- -ly shown in the figures.

The cam surfaces 23 and the hooks 22 are both arranged to cooperate with pins '26 which extend radially outwardly from the upper sleeve portion 2'! of the drilling bit body 4. These pins are two in number and are so positioned on the sleeve 21 that when the drilling bit is in operative position at the terminal section of the drill stem they will be engageable by a cam surface 23 wheneverthe cylindrical member of theretrieving ring is above the drilling bit with the splines cooperating with each other. This relationship is best shown in Figure 2 wherein the cylindrical member is in such axial position on the terminal section that a cam. surface is shown just engaging a pin 26. As thecam-surface 23 moves to engage pin 26 the hook will pass alongside the pin and not interfere with its reception in the notch 24.

In order that the retrieving ring may be lowered from and raised to the top of a hole being drilled, thesections have connected thereto cables somewhat to get the bit off the bottom of the 76 by the arrow in Figure 1.

hole. The ring'may be readily placed in surirounding relation with respect to the drill stem by removing the connecting bolts between the 'sections and after placing the sections on opposite-sides-of the-drill stem connecting such sections together again. When the ring reaches the terminal section 2 the splines on the sections of the retrieving ring and on the terminal section of the drilling stem will assume cooperating relationship. 'When this occurs two of the cam surfaces 23 will lee-directly above ithe two diametrically opposite pins on the sleeve portion of the drilling bit. As the retrieving ring approaches the drilling stem it should be allowed to drop freely and because of its considerable weight it will produce a hammer'blowon the pins 26 which will occur when the portions of the cam surfaces adjacent the open ends of the notch contact the pins. Because of the angular position of the cam surface with respect to the axis of the ring, the downward force produced by the retrieving ring will have a component transferred to the drilling bit which will act onrthe drilling bit in a tangential direction and thus produce a turning force which will be inn-direction to rotate :the drilling bit forwardly with respect to stem,

it being understood that the drilling stem is not rotatingat the time that the rerieving ring is being operated. As the drilling bit is rotated relative to the terminal section of the drill stem the cam surfaces 23 will continue to move axially relative to thepins 26 and each pin-will be guided into the upperend of a notch where it will engage the axial surface 25 opposed'to the cam surface. When the pins reach the positions the drilling bit will have been rotated relative to the terminal section-of the stem a sufficient distance to bring the pins 1 of the bit into the axial portion of the L-shaped grooves '6. The drilling bit is now ready to be raised to the top of the well and this is'accomplished merely by pulling up on the retrieving ring. As the retrieving ring is pulled up the pins 26 will be engaged by hooks 22 and the bit carried upwardly along with the retrieving ring. 'When the bit is at the top of the well the cutters may be changed and then the hit again lowered and re-connected to'the terminal section of the stem. The lowering could be accomplished by the retrieving ring shown, but I prefer to do it in a more efficient manner by another ring which forms no part of this in- "vention. 'If the drilling bit should not be'turned by the retrieving ring when first dropped, the ring may be raised and the action repeated, thus producing successive hammer blows on the pin --26 to bring about such turning of-the drilling bit that it will be in a position to be'slid upwardly on the drillstem.

It will be noted in connection with the retrieving ring that when it is operated there is no possibility of the drill stem being rotated in a directionreverse'to its drilling direction, as indicated The splines prevent any relative rotation between the retrieving ring and the stem and because of this the cam surface will cause the ring to act as a wedge between the terminal section of the drill stem and the drillin bit to thus turn the drilling bit in a disconnecting direction. Thus there is no possibility of any of the stem joints becoming loosened or unscrewed as could happen. The retrieving ring is very simple in construction and can be made as heavy as desired. It may be readily positioned in surrounding relation to the drill stem and at the top of the well and removed therefrom because of the separable sections.

Being aware of the possibility of modifications in the particular structure described without departin from the fundamental principles of my invention, I do not intend that the scope of the invention be limited in any manner except in accordance with the appended claims.

What is claimed is:

l. A retrieving ring for use with a drilling bit capable of disconnection from a drill stem by a relative turning movement, said ring comprising a member surrounding the stem and slidable thereon, means on the ring member for cooperation with means on at least a part of the stem adjacent the bit for preventing relative rotation of the ring member and stem, said member being provided with a cam surface for cooperation with a part of the bit to transfer an axial force created by axial movement of the member into a turning l'crce acting on the bit, and means carried by the member for connecting it to the bit to raise the bit after it is disconnected from the stem.

2. A retrieving ring for use in disconnecting and removing a removable drilling bit from the end of a drill stem while the stem remains in the hole being drilled, said ring comprising a cylindrical member provided at its lower end with a cam surface and a hook, said cam surface and the hook being so positioned on the member and so related to each other that a part carried by the drill bit can be engaged by the cam surface and upon downward axial movement of the ring rotate the drill bit and so place the part in a position that it will be engaged by the hook upon upward movement of the ring, and means on the inner surface of the cylindrical member for preventing its turning on at least the portion of the stem adjacent the bit but permitting axial sliding movement.

3. A retrieving ring for use in disconnecting and removing a removable drilling bit from the end of a drill stem while the stem remains in the hole being drilled, said ring comprisin a cylindrical member with its lower end being provided with a generally V-shaped notch and a hook at the open end of the notch extending from one surface thereof, and means on the inner surface of the member for preventing its turning on the stem but permitting axial sliding movement.

4. A retrieving ring for use in disconnecting and removing a removable drilling bit from the end of a drill stem while the stem remains in the hole being drilled, said ring comprising a cylindrical member provided with means for cooperation with means on the stem for non-rotatable sliding movement on said stem and being provided at its lower end with an open notch, one side of which extends substantially axially and the other side of which provides an angularly related cam surface for engaging a part of the bit to cause rotation thereof relative to the stem by an axial movement of the cylindrical member,

'said member also being provided with a hook at the end of the axial surface which extends into the open end of the notch and adapted to connect with said part engaged by the cam surface.

5. In a retrieving ring for use in disconnecting and removing a removable drilling bit from the lower end of a drill stem while said stem remains in the hole being drilled, said ring comprising a member for sliding movement on the stem and provided with axial slots in the member for receiving axial ribs on the stem and means on the lower end of the member providing a cam surface and a hook for cooperation with a projection on the bit, said cam surface and hook being so arranged on the member and related to the bit projection that an axial movement of the member will cause the cam surface to apply through the projection a disconnecting turning force to the bit and place the projection in a position to be engaged by the hook.

6. A retrieving ring for use in disconnecting and removing a removable drilling bit from the end of a drill stem while the stem remains in the hole being drilled, said ring comprising a cylindrical member composed of arcuate sections separably secured together, means carried by the sections on the inside thereof for cooperation with means on the drill stem for permitting sliding of the cylindrical member but preventing its rotation on the drill stem, two of said sections at their lower ends being provided with means for cooperation with a part of the drilling bit for rotating said drilling bit relative to the stem by an axial movement of the cylindrical member and also being provided with means for cooperation with means on the drilling bit for connecting the cylindrical member to the bit for raising said bit up the drill stem with the cylindrical member.

'7. A retrieving ring for use in disconnecting and removing a removable drilling bit from the end of a drill stem while the stem remains in the hole being drilled, said ring comprising a cylindrical member composed of two semi-cylindrical elements separably secured together, circumferentially spaced axially extending members carried by the inside of said semi-cylindrical elements for providing circumferentially spaced slots for slidable receiving ribs on the drill stem, said axially extending members being V-shaped at their lower ends, each of said semi-cylindrical elements at its lower end being provided with a cam surface and a hook, said cam surface and hook being so arranged on the semi-cylindrical member and so related to each other that a part carried by the drill bit can be engaged by the cam surface and upon downward axial movement of the ring rotate the drill bit and so place the part in a position that it will be engaged by the hook upon upward movement of the ring.

8. In apparatus of the class described, a drill stem, a drilling bit attachable to and detachable from the stem by relative rotary movement and provided at its upper end with a sleeved portion, a retrieving ring, a cable connected thereto for raising the ring, splines on the inner surface of the ring, cooperating splines on the stem adjacent its lower end and above the drill bit, the upper end of the splines on the stern and the lower end of the splines on the ring being of V- shaped formation, said ring at its lower end being provided with a cam surface and an opposed hook, and a projection on the sleeve of the bit for cooperation with the cam surface and the hook, said cam surface being related to the axis of the ring and the hook that upon the downward movemerit of the ring "the projection will be engaged by the cam surface to rotate the bit and upon rotation of the bit 'said projection will be positioned so as to be e'ngageable by the hook upon upward movement of the ring.

9. A retrieving ring for use with a drilling bit which is disconnectable from a drilling stem by arotatable movement'while the'stem remains stationary in the hole, said ring comprising a member constructed with a bore to permit free slid- 'ing movement on the stem from the top of the well to the bit, means carried by the inner portion of the ring member for cooperation with means on the lower portion of the drill stern ad- 'jacent the bit to'prevent "relative rotation of the ringmember and'stem, and means carried by the lower 'end of said member for cooperation with means on the bit for rotating the bit relatively to the stem to disconnecting condition by weight of the ring during an axial movement only of the J member and including means for connecting the member to the bit after the bit is rotated 50 that the bit can beraised upthe-stem relatively there- 'to with the member after it is disconnected.

CARL C. KOELN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

